I divide my yearly Khums into two parts: One part goes to my local center, which is an authorized agent for Khums and from whom I receive a receipt, and the other part goes directly to orphaned children from a Shia orphanage overseas, where I visit annually and personally ensure the children receive the money. Is the latter part of my Khums (for the orphanage) still valid, if I do not receive a receipt? I was not aware of this condition in the past, and I am not sure if it would be feasible to get the proper receipt from the orphanage in the future. Please let me know if this is still valid, as I hope to continue to offer relief to the orphans through my Khums in the years to come inshallah.
As obligated by Islamic law, the entire amount of khums is divided into two portions, sahm al-Imam and sahm as-sadah, which are the portions due to the Imam (atf) and the sayyids who are poor, respectively. During the present time of occultation of the Imam (atf), the former should be given to a Mujtahid, who fulfils all conditions, or be spent for such purposes as allowed by that Mujtahid (e.g. by giving to those entities, like centers and organizations, authorized by the religious authority to accept and spend the part of the Imam (atf) for valid purposes).
See for more details: https://www.sistani.org/english/book/48/2293/
If a center is authorized to receive khums, your official religious receipt must still come from the office of the Jurist (Marja) or his authorized representative such as IMAM. Furthermore, you may send your khums to other entities, such as an orphanage, as long as they have a written permission to accept khums, and they provide you with an official receipt from the Jurist’s (Marja’s) office.
Hence, the rules mentioned above need to be followed when distributing the two parts, and in the case of this specific question, the amount going to the orphanage needs to be designated accordingly (i.e. sahm al-Imam vs. sahm as-sadah).
Whether the part you sent to the orphanage is valid or not depends on fulfillment of the aforementioned conditions. Please note that if a person does not receive an official receipt for sahm al-Imam then it is not considered valid: https://www.stageimam.theedemo.com/khums-needs-official-receipt/